Patterning system for a multi-feed circular knitting machine

ABSTRACT

A multi-feed circular knitting machine equipped with needles selectively raised to different heights by jacks having patterning butts arranged to be acted upon by air-operated selector cams. The latter are in pairs stacked into housings, one in advance of each feed. The two cams of each pair are for raising needles, via jacks, to tucking and clearing heights respectively. To each stack of selector cams there is a block of fluidic elements with sensing orifices in alignment with channels of information carried by a punched tape or an apertured drum driven in time with the machine. The selector cams are pushed forward by low pressure air and retracted by induced vacuum. The jacks are in a cylinder larger than a cylinder accommodating the needles, movement transmitting and amplifying levers being provided between the two whereby short movements of the jacks are converted into longer movements of the needles.

United States Patent [191 Wills-Moren et al.

[ PATTERNING SYSTEM FOR A MULTI-FEED CIRCULAR KNITTING MACHINE [75]Inventors: William James Wills-Moren,

Stevington; Walter Goadby, Evington, both of England [73] Assignee:Camber International (England) Limited, Leicester, England [22] Filed:July 6, 1971 .1 1 RRl-hN9-Fl l i s c [30] Foreign Application PriorityData 7, Jil 2 21922199 1 Britain [52] US. Cl 66/50 R [51] Int. Cl D041)15/68 [58] Field of Search... 66/50 R, 50 A, 50 B, 25, 40,

66/42, 36 A, 36 B, 8, 154 A; l37/8l.5

[56] References Cited UNITED STATES PATENTS 3,270,960 9/1966 Phillipsl37/8l.5 UX

3,274,800 9/1966 Mishcon et a1. 66/50 A 3,586,061 6/1971 Lauritsen66/154 A 3,587,251 6/1971 Vincoli 66/8 3,664,383 5/1972 Minchey et al.66/154 A X 3,683,644 8/1972 Chvala et al 66/8 FOREIGN PATENTS ORAPPLICATIONS 1,287,447 2/1962 France 66/8 1,930,522 l/l970 Germany66/154 A 2,031,089 l/l97l Germany 66/8 892,332 3/1962 Great Britain66/154 A Feb. 26, 1974 1,193,118 5/1970 Great Britain 66/50 R 522,5564/1955 Italy 66/50 R OTHER PUBLICATIONS Fluidics; New KnittingTechnology, The Hosiery Trade Journal, Vol. 78, N0. 930, June 1971, pp.138 & 139.

Primary Examiner-Wm. Carter Reynolds Attorney, Agent, or FirmLarson,Taylor and Hinds 5 7] ABSTRACT A multi-feed circular knitting machineequipped with needles selectively raised to different heights by jackshaving patterning butts arranged to be acted upon by air-operatedselector cams. The latter are in pairs stacked into housings, one inadvance of each feed. The two cams of each pair are for raising needles,via jacks, to tucking and clearing heights respectively. To each stackof selector cams there is a block of fluidic elements with sensingorifices in alignment with channels of information carried by a punchedtape or an apertured drum driven in time with the machine. The selectorcams are pushed forward by low pressure air and retracted by inducedvacuum. The jacks are in a cylinder larger than a cylinder accommodatingthe needles, movement transmitting and amplifying levers being providedbetween the two whereby short movements of the jacks are converted intolonger movements of the needles.

5 Claims, 9 Drawing Figures PATENTED FEB26 I974 sum 1 BF 6 PATENTEDFEB26 I974 SHEEI 2 0F 6 PATENTEI] FEBZB I974 SHEET 6 BF 6 PATTERNINGSYSTEM FOR A MULTI-FEED CIRCULAR KNITTING MACHINE This invention relatesto a patterning system for a multi-feed circular knitting machine, andhas reference particularly to such a system of the kind comprising, incombination, groups of individually movable selector cam members, onegroup in advance of each feed, arranged around the knitting head of themachine, individually operable instruments accommodated in tricks of anaxially tricked cylinder co-axial with respect to the knitting machinehead, said instruments being furnished with patterning butts, onepatterning butt per instrument, so disposed in a multiplicity ofsuperimposed planes as to enable them to be operated upon by theselector cam members to effect selective actuation of the instruments,and, for each group of selector cam members, programmed control meansfunctioning at a speed related to that of the machine for selectivelyoperating the said cam members in advance of the relevant feed inaccordance with predetermined patterning requirements.

Although there is no limitation in this respect, it is principally theintention that the patterning system of this invention shall be for theselective actuation, under control, of individually operable knittingneedles whereby the latter are caused either to knit or to tuck or tonon-knit, according to patterning requirements. In this regard, theaforementioned instruments, broadly considered, may be the knittingneedles themselves. More usually, however, the butted instruments willbe in the nature of needle-actuators, such as jacks or sliders, entirelyseparate from the needles and, for this reason and where the context soadmits, will hereinafter for convenience be referred to as patterninstruments."

Moreover, it is primarily the intention to apply the invention to acircular multi-feed knitting machine of the rotary needle cylinder type,in which instance the individually operable needles and their actuatingpattern instruments move round with the knitting head, whereas thegroups of selector cam members and the programmed control means forselectively operating the same are associated or combined with thestationary cam box or shell surrounding the rotary needle cylinder, orsuperimposed needle cylinders, as the case may be.

It would, however, alternatively be possible to apply the invention to amulti-feed machine of the stationary needle cylinder type, in which casethe groups of selector cam members and the programmed control meanstherefor would be required to revolve together with the annular cam boxor shell.

Whilst the invention is applicable to multi-feed double cylindermachines and machines of the cylinder and dial type, it is expected thatthe principle field of application will be to multi-colour Jacquardsingle cylinder body machines having cylinders of comparatively largediameter and relatively large numbers of feeds.

As to the disposition of the pattern instrument patterning butts in amultiplicity of superimposed planes as aforesaid, this will usually besuch as to enable the patterning butts in any one horizontal plane to bewell spaced apart circumferentially; in such an arrangement, the buttson successive pattern instruments are so relatively offset laterally inthe superimposed planes as to form right around the machinecircumferentially spaced inclined, i.e., diagonal, lines of butts, thelateral offsetting corresponding, of course, with the pitch of thepattern instruments circumferentially of the machine. But it isconsidered that other dispositions of pattern instrument butts may beadopted within the broad scope of the invention.

The invention may most advantageously be applied to the particulararrangement of pattern jacks in which these jacks are accommodated intricks formed in a separate jack cylinder which is co-axial with, but ofa larger diameter than the needle cylinder, the butts on the jacks beingset out in circumferentially spaced inclined or diagonal lines(hereinafter more fully described) but with the vertical pitch of saidbutts reduced to such an extent that lifting movements imparted to thepattern jacks by action upon their butts of jack selector cams are lessthan sufficient to raise the corresponding needles to the heightsrequired. The particular arrangement just described thus essentiallyalso includes the provision, between the pattern jacks in the separatecylinder and the corresponding needles in the needle cylinder, of meansof any suitable character, e.g., levers, for transmitting to the needlesand simultaneously amplifying the lifting movements imparted to thejacks by the selector cams.

A patterning system of the kind herein referred to applied to amulti-feed circular knitting machine has heretofore often been whollymechanical. Whilst such a mechanical system enables a wide range ofpatterns to be produced consistent with a reasonable system cost, itsphysical space limitations restrict the number of yarn feeds possibleand the amount of data that can be contained in the control or programmemedia or component. This restricts both the rate of output of knittedfabric and the possible pattern area before repeats of pattern arenecessary. In order to overcome these limitations, systems havepreviously been developed using programme media other than mechanical.One example is by use of a programme stored on a film which is read byphotoelectric means. The electrical pulses are then used to influencethe needle operation by the use of a solenoid for each needle. Such anelectro-magnetic system overcomes most of the technical limitationsimposed by the mechanical system but is expensive and very complex. Datamust be read at a high rate, this again limiting the number of yarnfeeds and output rate but allowing the much more comprehensive patternarea than a mechanical system.

The object of the present invention is to provide, in a multi-feedcircular knitting machine, a generally improved patterning system of thekind concerned designed not only to increase the patterning potential,but also to permit as many feeds as possible to be incorporated in themachine, thus maintaining a high output rate of patterned knittedfabric, without either necessitating complex data preparation orincurring prohibitive cost.

The improved patterning system according to this in- In accordance withan important aspect of the invention, there is preferably provided aseparate predeterminedly apertured and movable programming element orcomponent and means for reading the same at each selector station. Sucha unitary, self-contained system for each feed makes possible extensivepatterning potential coupled with high output rates. In this connectionit has to be realised that the rate at which information must be readand transmitted to the selector cam members would usually be too greatfor a central data element or component reading device to be employed.It is considered that development of such a centralised control systemalthough not altogether excluded from the scope of this invention, wouldprobably incur a prohibitively high development cost, with the risk thatthe resulting equipment, even though technically successful, would betoo expensive for the market to accept.

In any event, there are in the preferred embodiment of the invention,provided in each separate programming element or component as manychannels of information, i.e., lines of holes predeterminedlyinterspersed with un-apertured portions, as there are selector cammembers in the group at each selector station: this enables relativelylow reading speeds to be adopted.

The controlled air pressure system at each selector station may bewholly pneumatic in character, in which instance the movable aperturedprogramming media or component ma itself constitute valve means tocontrol the admission of pressurised air into or the cutting off of suchair from conduits in line with the selector cam members of the relevantgroup. Alternatively, in a pneumatic system, the apertured programmingmedia or components may be used to influence air valves of the diaphragmor any equivalent type.

It is, however, considered that the most suitable air pressure systemfot the intended purpose may prove to be a truly fluidic one in whichthere are no moving parts; in such a system, a continuously flowingstream of main pressure air, confined within a conduit, would either beallowed to flow idly past a selector cam member or be diverted forrendering the said member operative by a fluidic switch or an amplifierresponsive to a subsidiary low pressure air jet in turn controlled bythe presence or absence of a hole in the apertured programming elementor component. In other words, the presence of a hole enables a signal,in the nature of an emission, i.e., puff, of low pressure air, to passto a fluidic switch or an amplifier the output from which operates theselector cam member.

Accordingly, the expression air pressure system herein used is intendedto be a generic one sufficiently wide to cover any of the foregoingarrangements.

But whatever the precise nature of the air pressure system adopted, aselector cam member may be acted upon by air under pressure eitherdirectly or through the medium of a piston or a plunger movable axiallywithin the relevant air conduit. Return of a selector cam member to itsinoperative position, preparatory to re-selection after having beenoperated, may be effected either by fluidic, pneumatic or mechanicalmeans. As examples of mechanical means may be mentioned, firstly, aspring, e.g., of the leaf type, and, secondly, a cam-like protuberanceon the needle cylinder designed to push back the selector cam member asa consequence of rotation of the knitting head.

The selector cam members at each selector station may consist either offulcrummed levers or of rectilinearly movable slides. In either event,the said members may advantageously be banked one above another in asuitable housing located at the selector station, the operative portionsof the members being in the nature of inclined cams.

It has previously been stated that the knitting needles are causedeither to knit, or to tuck or to non-knit, according to patterningrequirements. In this regard, the projection of a selector cam memberinto its operative position by air pressure may serve, either directly,or through the medium of pattern instruments (with or without associatedlift-amplifying means) to raise relevant needles either to clearingheight or tucking height so that these needles will either knit or tuckrespectively. In such a case, any needles not so raised will non-knit.Broadly considered, however, the arrangement could be reversed so thatwhilst all needles will normally either knit or some knit and otherstuck, only those needles which fail to be raised, by selectiveretraction of previously operative cam members, will be caused tonon-knit.

In order that the invention may be more clearly understood and readilycarried into practical effect, specific embodiments thereof will now bedescribed with reference to the accompanying drawings, wherein,

FIG. 1 is a vertical sectional view taken through the knitting head of acircular multi-feed knitting machine of the rotary needle cylinder type,this figure showing a pattern jack in a separate jack cylinder; a levertransmitting to the corresponding needle and amplifying the liftingmovement imparted to the said jack by selector cam slides; a bank offluidic elements with their respective selector cam slides at a selectorstation; and an apertured programming element in the form of a punchedtape,

FIG. 1A is a detail vertical sectional view showing more clearly one ofthe pattern jacks,

FIG. 1B is a fragmentary portion of FIG. 1 drawn to a larger scale,

FIG. 2 is a detail perspective view showing a pair of the selector camslides, a succession of the pattern jacks, and two of the needles and ofthe corresponding intermediate movement transmitting and amplifyinglevers,

FIG. 3 is a detail inner end view, as seen when looking outwardly fromthe centre line of the knitting head, of a few of a bank of fluidicelements together with their selector cam slides, and illustrates howthese slides elevate jacks to different positions heightwise,

FIG. 4 is a plan view looking down on a few of the banks of fluidicelements and the corresponding control tapes,

FIG. 5 is a developed layout showing, in purely diagrammatic fashion, afew of the inclined or diagonal lines of patterning butts on patternjacks, pairs of selector cam slides included in the banks at twoselector stations and fragmentary portions of pattern jacks,

FIG. 6 is a part-sectional plan view of one of the fluidic elements perse, shown in relation to the punched control tape at the relevantselector station, the selector cam slide of the said element beingdepicted in its inwardly projected operative position, and

FIG. 7 is a view similar to FIG. 6 but showing the same selector camslide retracted outwardly to its inoperative position.

Like parts are designated by similar reference characters throughout thedrawings.

Referring to FIG. 1, it will be seen that the illustrated multi-feedcircular knitting machine includes a rotary needle cylinder which isperipherally tricked at 10a to receive individually slidable knittingneedles 11 of the pivoted latch type. Each needle has an operating butt11a. The machine is also furnished, for cooperation with the needles,with outside holding-down sinkers such as 12 which are radially slidablein a horizontally disposed sinker bed 13 and are operated by camsmounted in a sinker cam cap 14.

For selectively raising the needles 11 there is provided a correspondingcircular series of pattern jacks such as that indicated at 15 in FIG. 1Aone to each needle. These jacks are accommodated in tricks 16a formed ina separate jack cylinder 16 which is co-axial with, but of a largerdiameter than the needle cylinder 10. At its lower end the needlecylinder 10 seats within a recess 17a formed in the top of a ring 17which in turn fits within, and sits upon an internal shoulder 16b formedon, the jack cylinder 16. The needle cylinder 10 is firmly attached tothe ring 17 and the latter is secured to the jack cylinder. The lowerend of this jack cylinder has bolted to it the conventional cylinderdriving gear 18. Accordingly, when the gear 18 is driven from the drivesource customary in such a machine, the needle cylinder 10 and the jackcylinder 16 will rotate together at the same speed.

Although the size of the machine, the number of feeds with which it isequipped and the rotational speed of the knitting head may vary widely,the particular machine now being described is assumed to have thefollowing specification:

Needles per inch28 Needle cylinder diameter-26 inches Cylinder speedupto 20 rpm.max.

Number of feeds-78 A 30 inch machine having ninety feeds is a practicalproposition commercially.

It is convenient here to mention that in FIG. 1 the jack trick 16a isshown as being empty so that the form of the trick can be fully seen:for this reason the pattern jack 15 in the next trick is for the mostpart hidden in FIG. 1 by the relevant trick wall. But in FIG. 1A apattern jack 15 is fully shown.

As will be seen, the stem of each pattern jack 15 is furnished with onlyone patterning butt 15a; at its lower end each such jack is providedwith a butt 15b arranged to be acted upon by cams such as 19 by means ofwhich jacks, after being raised, are restored to their originalpositions for re selection. The upper end of each pattern jack isincreased somewhat in width, from its back edge to its front edge, toprovide an abutment 150 having a rounded, i.e., semicircular, upperextremity for a purpose hereinafter to be described. The singlepatterning butts 15a on the pattern jacks 15 are provided at differentpoints along their straight stems so that these butts are disposed in amultiplicity of superimposed horizontal planes. The particulardisposition of the illustrated butts is such as to enable the patterningbutts 15a in any one such plane to be well spaced apartcircumferentially. That is to say, the butts 15a on successive patternjacks 15 are so relatively offset laterally in the superimposed planesas to present right around the jack cylinder 16 circumferentially spacedinclined, i.e., diagonal, lines of butts, the lateral offsettingcorresponding, of course, with the pitch of the pattern jackscircumferentially of the machine. One such inclined line of patterningbutts is clearly shown in FIG. 2. Moreover, three complete inclinedlines L2, L3 and L4 of patterning butts 15a and a part of such a line L]are also depicted in FIG. 5. The pitch P of these inclined linescorresponds with a circumferential distance sufficient to accommodate asuccession of 36 of the pattern jacks 15. Thus, in each inclined linethere are 36 patterning butts 15a. The direction of cylinder rotation isindicated by the horizontal arrow at the bottom of FIG. 5. Assuming thepatterning butts in each line to be differentiated by virtue of beinglettered downwards in the sequence A, B, C, D-, these lettersdesignating the superimposed planes, then the pattern jack 15 at theright-hand side of FIG. 5 is shown as having a butt in the top plane A,whereas the jack 15 has a butt in the plane R.

Preferably, the vertical pitch of the patterning butts 15a on successivepattern jacks 15 is such that the lower edge of the butt on any one jackis spaced vertically from the corresponding edge of the butt on the nextjack a distance equal only to the overall vertical dimension of a singlebutt. In this preferred case, therefore, an individual selected jack canonly be lifted a distance equivalent to the vertical pitch of the butts.

Advantageously, the patterning butts 15a may, as shown, be of saw-toothform, having horizontal lower edges and upper edges which inclinedownwardly and outwardly from the stems of the jacks 15. By virtue ofthis particular shaping of the butts, inner operative cam portions ofselector cam slides (hereinafter to be described) are enabled to beinserted beneath the horizontal lower edges of butts and well into thespaces between butts.

Since each pattern jack 15 is arranged to be lifted only minimalvertical distances, there must, as previously mentioned herein, beprovision between the jacks in the separate cylinder 16 and thecorresponding needles l 1 in the needle cylinder 10 of means fortransmitting to the needles and simultaneously amplifying the liftingmovements imparted to the jacks by the aforementioned selector camslides. Conveniently for this purpose there are provided, as shown inFIGS. 1 and 2, simple, radially extending movement-transmitting andamplifying levers 20 between the upper ends of the pattern jacks l5 andthe lower ends of the needles 11. These levers 20 thus extend across theannular space S between the two co-axial cylinders 10 and 16 ofrespectively different diameters and are located beneath the customaryannular cam box or shell (not shown) surrounding the needle cylinder 10.The outer end of each of the movement-transmitting and amplifying levers20 is formed with a near-circular fulcrum 20a which is seated in asuitably formed ring 21 combined with the upper end of the pattern jackcylinder 16. To enable them to avoid interference with the jack cylinder16, the pivoted levers 20 may, as shown in FIGS. 1 and 1A, be ofupwardly arched form. In any event, the semicircular upper extremitiesof the aforementioned abutments 15c of the pattern jacks 15 act upon thelower edges of the levers 20 at carefully predetermined points fairlyclose to the near-circular fulcrum 20a so that comparatively smalllifting movements of the jacks l5 imparted by the jack selector slidesnow tobe described are magnified into substantially greater heightwisemovements of the inner ends of the said levers.

These ends are forked as indicated at 20b to embrace and act uponoutwardly directed butts 11b at the lower extremities of the needles 11.

The jack selector slides at each selector station SS are arranged in avertical bank of superimposed pairs. The selector slides of each pairare hereinafter for convenience designated 22A and 22B. There are, ofcourse, as many selector stations SS around the knitting head of themachine as there are feeds. Only two of these stations arediagrammatically illustrated in FIG. 5. The idea is that the operativecam portion of one of the slides, say the slide 22A of each pair shallhave an outwardly directed cam face 23 adapted, by engagement with butts15a, to lift relevant pattern jacks 15 sufficiently to causecorresponding needles 11, through the medium of themovement-transmitting and amplifying levers 20, to be raised to tuckingheight, whereas the operative cam portion of the companion slide 22B ofthe pair shall have an upwardly directed cam face 24 which, togetherwith the cam face 23 of the slide 22A, lifts pattern jacks 15 to anextent sufficiently far to cause corresponding needles to be raised toclearing height. The cam faces 23 and 24 are gently inclined at lessthan to the horizontal. The butt ends of the slides 22A and 22B are, ineffect, similar to pistons of air cylinders, In FIG. 3 (as seen lookingoutwardly from the centre line of the machine), the normal run height ofa patterning butt 15a is indicated at RH. A butt 15a is lifted to heightTH by a cam face 23 to position the corresponding needle at tuckingheight, whereas such a butt is lifted to height CH to position therelevant needle at clearing height preparatory to knitting. In FIG. 1,the pattern jack is raised only sufficiently to position thecorresponding needle at tuck height, the slide 22B being shown in itsretracted position. In FIG. 2, on the other hand, both of the slides 22Aand 228 shown are operative, their combined upwardly directed cam faces23 and 24 having just acted upon the patterning butt 15a of the slightlyraised pattern jack 15 to position the right-hand needle 11 at clearingheight. The left-hand needle in this figure is shown down in itsnon-knit position.

Of each such pair of jack selector slides, the slide 22A islongitudinally moved radially inwards into its operative position,independently of the slide 223 which latter remains stationary. On theother hand, whenever the slide 22B of the pair is moved radiallyinwards, the slide 22A is also caused to move forwardly togethertherewith. Each slide is arranged to traverse a distance of only 0.1inch in a radial direction to the machine cylinder.

In the preferred example illustrated in FIGS. 1 7, the major portions ofthe slides 22A and 22B are disposed in superimposed horizontal planes,only the operative cam portions of the said slides having facesappropriately inclined to the horizontal. In this preferred arrangement,whenever the slide 228 of a pair is selectively moved into its operativeposition, the companion slide 22A is as a matter of course, alsosimilarly moved into its operative position.

Alternatively, the selector cam slides in each vertical bank maythemselves be in parallel inclined planes with respect to the horizontalso that their operative portions can be in these same planes, the angleof inclination being such as to impart to the jacks 15 the requiredextents of lift, all as will be hereinafter more fully described withreference to FIGS. 8 and 9.

Each of the selector cam slides 22A and 22B is operable by air pressure,and the air pressure system employed includes fluidic elements 25 eachconsisting of a single laminate section having an accurately producedcavity to receive one of the said slides. Seventy two of these fluidicelements 25 are stacked one above the other to form a vertical block 26at each selecting station SS.

Each block 26 is supported upon an upstanding inner portion 270 of afixed annular plate 27 which latter is located near to the lower end ofthe jack cylinder 16 and is in turn secured upon the fixed bed plate 28of the machine. The seventy two fluidic elements 25 of each stack areclamped together between upper and lower plates 29 and 30 respectively,long screws, rivets or the like such as 31 being used to produce theclamping effect. The fluidic elements 25 are only 0.75 in. thick, thewhole block 26 measuring only 5.40 in. in height. This allows the jackcylinder 16 to be of a reasonable height.

As shown in FIGS. 6 and 7, each fluidic element has a sensing orifice 32in alignment with a channel or line of holes 33 punched in a programmingelement in the form of a punched tape PT. The orifice 32 extends alongthe median line of the fluidic element. This tape is adapted to bedriven at a linear speed corresponding with the rotational speed of theknitting head of the machine, i.e., of the two co-axial cylinders 10 and16. The tape PT, moreover, passes around a vertical tape guide 34 which,as shown in FIGS. 6 and 7, has a mainly convex front face 34a with aflat 34b thereon, a vertical exhaust duct 35 extending therethrough topractically the full height thereof and a vertical series of as many airexhaust slots 36 as there are selector cam slides 22A and 22B in thecorresponding bank. Thus, the air exhaust slots 36, of which there are72, are disposed one above the other, each of them communicating, on theone hand, with the interior of the vertical exhaust duct 35 common tothem all and, on the other hand, with the small vertical space 37provided between the aforementioned flat 34b and the opposed back of thetape. In the upstanding portion 27a of the fixed annular plate 27 isformed an annular air chamber 38 which is adapted to be continuouslysupplied with compressed air at low pressure. Such air may be suppliedfrom a low pressure, high volume turbo-blower which is mounted on themachine. Extending upwardly from the top of the air chamber 38 are airfeed channels 39 one per stack of fluidic elements 25. Each such airfeed channel 39 leads upwardly into the lower end of a vertical air tube40. This tube 40 extends upwardly through all of the superimposedfluidic elements 25 and has formed in its wall a vertical series of asmany air feed holes 41 as there are selector cam slides 22A and 22B inthe corresponding bank. The air feed holes 41, disposed one aboveanother, are in alignment both with the respective sensing orifices 32and also the corresponding air exhaust slots 36 in the tape guide 34.The inner end of each orifice 32 communicates with an annular channel 42formed in the relevant fluidic element 25. This channel extendspartially around the adjacent portion of the vertical air tube 40 andfreely communicates with the rear or back edge of the particularselector cam slide carried by the relevant fluidic element 25. The upperend of each exhaust duct 35 is aligned with a hole 43 (open toatmosphere) provided in a plate 44 constituting a part of a punched tapecassette 45. At 46 is represented a base plate of a cassette for, say,six tapes for controlling needle selection at six feeds of the machine.

Presence of a hole 33 in the appropriate channel or line of a punchedtape PT causes the relevant selector cam slide to retract in thedirection of the arrow in FIG. 7, whereas no hole causes the same slideto advance in the direction of the arrow in FIG. 6. The relative sizesof orifice 32 and hole 33, and the pitch between holes 33, are arrangedso that a continuous row of holes 33 is read as a continuous hole sothat the selector cam slide remains retracted. Obviously, a length oftape without holes will cause the slide to remain advanced. The space 37between the flat 34b on the front face of the tape guide 34 and theopposed back of a punched tape PT, which space is segment-shaped incrosssectional plan (see FIGS. 6 and 7), ensures that a hole 33 in thetravelling tape remains in communication with the vertical exhaust duct35, via the relevant air exhaust slot 36, for a sufficient length oftime to enable retraction of the corresponding selector cam slide tofully take place as and when the said hole 33 registers with thecorresponding orifice 32.

Thus, the illustrated air pressure system is such that whenever a hole33 in a punched tape PT is in such a position as to allow air to escapeto atmosphere through an air exhaust slot 36, the common exhaust duct 35and the hole 43 at the upper end of the latter, the pressure in thechannel 42 between the air feed hole 41 and the back of the relevantselector cam slide falls below atmospheric due to the Venturi effect.The result is that the slide is drawn inwards into its retracted, i.e.,inoperative position as shown in FIG. 7. But as soon as the punched hole33 passes, so that an unapertured portion of the tape is then blockingthe orifice 32, the pressure of the air issuing through the relevant airfeed hole 41 and passing into the annular channel 42 thereupon builds upabove atmospheric and the selector cam slide is advanced into itsoperative position as shown in FIG. 6.

A single hole 33 in, and an un-apertured blank portion of, a tape causesa tuck selection slide 22A to move forward. No holes cause both slides22A and 22B to move forward to raise the corresponding needles toclearing height. A double hole in the tape causes both slides of a pairto be retracted so that needles miss.

It will accordingly be appreciated that each selector station has itsown punched tape PT, the latter, as shown in FIG. 4, being in the formof an endless loop.

If required, each tape loop can be punched with a different pattern ofpunched holes. It will accordingly be readily appreciated that a patterncould, if required to do so, extend the full width of the fabric. Aspreviously mentioned, there is in each punched tape PT a separatechannel or line of holes 33 for each fluidic element 25 in thecorresponding stack. The pitch of the holes 33 along the length of atape is, in the specific example now being described, .0935 in. Sincethe machine is equipped with 2,304 needles, there are 64 hole positionsper revolution of the cylinders and '16, i.e., per 5.984 in. of tape. Asthe machine being described, merely by way of example, has 78 feeds itwill be realised that punched tapes of a reasonable and easy to handlelengthcan produce a pattern area of considerable depth.

Each punched tape PT is driven by means of a roller 47 having sprocketteeth 47a at each end for engagement in drive holes 48 in the tapemargins (see FIG. 1). At each end of the said roller there are 16sprocket teeth on a circular pitch of 0.187 in. Consequently, 32 holepositions are traversed past each sensing orifice 32 in a vertical block26 for each revolution of the corresponding toothed roller 47. If,therefore, the roller 47 is geared in such a way that it rotates twicefor each revolution of the cylinders 10 and 16, then 64 hole positionswill be allowed to pass each sensing orifice 32, i.e., one signal foreach inclined line of patterning butts 15a. Manifestly, machines havingdifferent needle pitches and different needle cylinder diameters tothose hereinbefore specifically quoted will incorporate differentgearing or employ different numbers of sprocket teeth according torequirements.

For convenience of handling and loading, the tapes and their drive andguide rollers are, as previously mentioned, mounted in cassettes 45 insets of six. Each cassette takes off a drive from the cylinder drivinggear 18 which is coupled in the manner depicted in FIG. 1 directly toone of the six toothed drive rollers 47 of the set. The remaining fivedrive rollers 47 of the set are driven from the first by means of atiming belt (not shown) passing over pulleys mounted on each driveroller spindle.

Each punched tape PT passes between a concave rear face of the relevantvertical block 26 of fluidic elements 25 and the mating convex frontface 34a of the tape guide 34, the two being lightly spring loadedtogether.

Referring again to FIG. 1, the particular toothed drive roller 47 showntherein is driven from the cylinder driving gear 18 through the mediumof a train of spur gearing. This train comprises a pair of intermeshedrotary gears 49 and 50 the axles 51 and 52 of which are fixed in thedriving gear 18. The rotary gear 49 meshes with a stationary gear ring53 which is secured to the fixed bed plate 28. The gear 50 is integraland rotatable together with a gear 54. The latter meshes with a gearwheel 55 arranged to drive a pinion 56. Lastly, the pinion 56 mesheswith a gear 57 secured to the lower end of the spindle 47b of the roller47. The spindle 56a of the pinion 56 rotates, as also does the spindle47b, in the fixed annular plate 27.

Each toothed drive roller 47 has co-operating therewith a plain guideroller 58, and three vertical guide pins 59, 60, and 61 extending upfrom the relevant base plate 46 are provided for the guidance of eachtape loop. Thus, as shown in FIG. 4, each punched tape PT passes betweenthe relevant rollers 47 and 58, around the rounded front of the tapeguide 34, then around the guide pins 59, 60 and 61 in that order.

One of the major advantages of the invention is that a control systemisattained without moving parts or electrical or electronic circuitry.The only mechanical movement is that which the control system initiates.It is this which leads to simplicity and low unit cost both for theknitting machine pattern programme and the selector units themselves. Anair control system has the added advantage that it is self-cleaning: airis discharged through working clearances in the system which helps todisperse dust and lint around the selector units themselves and theknitting elements. Air control also results in a minimum of wear on theoperating components within the selector units as they are, in a sense,working on air bearings.

We claim:

l. A multi-feed circular knitting machine comprising, in combination; anaxially tricked cylinder co-axial with respect to the knitting head ofthe machine; individually operable needle-controlling jacks which areaccomodated in tricks in the cylinder and are furnished with patterningbutts, one butt per jack, said butts on successive jacks being sorelatively offset laterally in a multiplicity of superimposed planes, asto form right around the machine circumferentially spaced inclined linesof the butts, the lateral offsetting corresponding with the pitch of thepattern jacks circumferentially of the machine; groups of individuallymovable selector cam slides, one group in advance of each feed arrangedaround the knitting head, and for each group of selector cam slides,programmed control means including an apertured programming elementfunctioning at a speed related to that of the machine for selectivelyoperating the said slides in advance of the relevant feed for effectingselective actuation of the jacks in accordance with pre-determinedpatterning requirements; the machine being characterized in that thevertical pitch of the said patterning butts on successive jacks is suchthat the lower edge of the butt on any one jack is spaced verticallyfrom the corresponding edge of the butt on the next jack a distanceequal only to the vertical pitch of the butts, whereby an individualjack can only be lifted by any one selector cam slide a distanceequivalent to the said vertical pitch; and in that each of the selectorcam slides in the group at a selector station in advance of each feed isoperable by an air pressure system and the supply of air under pressureto these slides is controlled by said apertured programming elementmovable in timed relation with the rotation of the knitting head of themachine whereby the selector cam slides are air operated selectively,the air pressure system in cluding fluidic elements each consisting of asingle laminate section having therein a cavity to receive one of theselector cam slides, twice as many of these fluidic elements as thereare patterning butts in each inclined line of such butts being stackedone above the other to form a vertical block at each selecting station,each fluidic element having a sensing orifice in alignment with achannel or line of information in the apertured programming element.

2. A multi-feed circular knitting machine according to claim 1, saidapertured programming element being a punched programming tape, andwherein the sensing orifices detect the presence or absence of holes insaid punched programming tape which extends around a vertical tape guidehaving a mainly convex front face fitted into a concave face of thevertical block of stacked fluidic elements, said tape guide havingformed therein an exhaust duct and a vertical series of as many airexhaust slots as there are fluidic elements in the stack, these slotsbeing aligned with the lines of information in the punched tape andcommunicating with the interior of the exhaust duct common to them all,and wherein a vertical air feed tube in communication with a source oflow pressure air extends up through the block of fluidic elements andhas formed in its wall as many air feed holes as there are fluidicelements in the stack, said air feed holes being in alignment both withthe corresponding air exhause slots and the respective sensing orifices,and the outer ends of the latter terminating in the concave face of thevertical block whilst their inner ends lead into channels freelycommunicating with the inner butt ends of the selector cam slides in therespective fluidic elements.

3. A circular knitting machine according to claim 2, wherein air underlow pressure is fed into the blocks of stacked fluidic elements at theselector stations from an annular chamber formed in a fixed plate whichsurrounds a rotary cylinder wherein are accommodated the instrumentsfurnished with the patterning butts.

4. A multi-feed circular knitting machine according to claim 1, whereinthe selector cam slides in the group at each selector station arearranged in superimposed pairs, the first slide of each such pair havingan operative end adapted by engagement with patterning butts, to raisecorresponding needles to tucking height only, whereas, the second slideof the pair has an operative end which, together with the operative endof the first slide, causes patterning butts to be lifted sufficientlyfar as to cause corresponding needles to be raised to clearing height,the arrangement being such that the first cam slide is movable into itsoperative position independently of the second cam slide, which latterremains stationary, whereas whenever the second slide is renderedoperative the first slide is also rendered operative together therewith.

5. A multi-feed circular knitting machine in accordance with claim 1,said apertured programming element being a punched tape, and wherein fordriving an endless loop of said punched tape at each selector stationthere is provided a driveable roller having sprocket teeth forengagement in drive holes in the tape loop, the said rollers at adjacentselector stations being mounted in a removable cassette and wherein atleast one of the driveable sprocket rollers in the cassette is drivenfrom a cylinder driving gear through the medium of a train of gearing.

1. A multi-feed circular knitting machine comprising, in combination; anaxially tricked cylinder co-axial with respect to the knitting head ofthe machine; individually operable needlecontrolling jacks which areaccomodated in tricks in the cylinder and are furnished with patterningbutts, one butt per jack, said butts on successive jacks being sorelatively offset laterally in a multiplicity of superimposed planes, asto form right around the machine circumferentially spaced inclined linesof the butts, the lateral offsetting corresponding with the pitch of thepattern jacks circumferentially of the machine; groups of individuallymovable selector cam slides, one group in advance of each feed arrangedaround the knitting head, and for each group of selector cam slides,programmed control means including an apertured programming elementfunctioning at a speed related to that of the machine for selectivelyoperating the said slides in advance of the relevant feed for effectingselective actuation of the jacks in accordance with pre-determinedpatterning requirements; the machine being characterized in that thevertical pitch of the said patterning butts on successive jacks is suchthat the lower edge of the butt on any one jack is spaced verticallyfrom the corresponding edge of the butt on the next jack a distanceequal only to the vertical pitch of the butts, whereby an individualjack can only be lifted by any one selector cam slide a distanceequivalent to the said vertical pitch; and in that each of the selectorcam slides in the group at a selector station in advance of each feed isoperable by an air pressure system and the supply of air under pressureto these slides is controlled by said apertured programming elementmovable in timed relation with the rotation of the knitting head of themachine whereby the selector cam slides are air operated selectively,the air pressure system including fluidic elements each consisting of asingle laminate section having therein a cavity to receive one of theselector cam slides, twice as many of these fluidic elements as thereare patterning butts in each inclined line of such butts being stackedone above the other to form a vertical block at each selecting station,each fluidic element having a sensing orifice in alignment with achannel or line of information in the apertured programming element. 2.A multi-feed circular knitting machine according to claim 1, saidapertured programming element being a punched programming tape, andwherein the sensing orifices detect the presence or absence of holes insaid punched programming tape which extends around a vertical tape guidehaving a mainly convex front face fitted into a concave face of thevertical block of stacked fluidic elements, said tape guide havingformed therein an exhaust duct and a vErtical series of as many airexhaust slots as there are fluidic elements in the stack, these slotsbeing aligned with the lines of information in the punched tape andcommunicating with the interior of the exhaust duct common to them all,and wherein a vertical air feed tube in communication with a source oflow pressure air extends up through the block of fluidic elements andhas formed in its wall as many air feed holes as there are fluidicelements in the stack, said air feed holes being in alignment both withthe corresponding air exhause slots and the respective sensing orifices,and the outer ends of the latter terminating in the concave face of thevertical block whilst their inner ends lead into channels freelycommunicating with the inner butt ends of the selector cam slides in therespective fluidic elements.
 3. A circular knitting machine according toclaim 2, wherein air under low pressure is fed into the blocks ofstacked fluidic elements at the selector stations from an annularchamber formed in a fixed plate which surrounds a rotary cylinderwherein are accommodated the instruments furnished with the patterningbutts.
 4. A multi-feed circular knitting machine according to claim 1,wherein the selector cam slides in the group at each selector stationare arranged in superimposed pairs, the first slide of each such pairhaving an operative end adapted by engagement with patterning butts, toraise corresponding needles to tucking height only, whereas, the secondslide of the pair has an operative end which, together with theoperative end of the first slide, causes patterning butts to be liftedsufficiently far as to cause corresponding needles to be raised toclearing height, the arrangement being such that the first cam slide ismovable into its operative position independently of the second camslide, which latter remains stationary, whereas whenever the secondslide is rendered operative the first slide is also rendered operativetogether therewith.
 5. A multi-feed circular knitting machine inaccordance with claim 1, said apertured programming element being apunched tape, and wherein for driving an endless loop of said punchedtape at each selector station there is provided a driveable rollerhaving sprocket teeth for engagement in drive holes in the tape loop,the said rollers at adjacent selector stations being mounted in aremovable cassette and wherein at least one of the driveable sprocketrollers in the cassette is driven from a cylinder driving gear throughthe medium of a train of gearing.